The presentation of quality sound production in moving automobiles, boats and aircraft is particularly challenging due to the high noise content of the environment in which the sound is presented. The bass response in such a system is generally inadequate. The bass response can be increased (“boosted”) with an equalizer, but this muffles the treble, resulting in a muffled quality audio.
In addition to muffling treble, a bass boost undesirably increases the dynamic range of the sound presentation. In a noisy environment, there is a relatively small range between the volume floor set by the noise (typically 80 dB in moving vehicles) and the volume ceiling set by the physiology of the ear. In a noisy environment, increases in the dynamic range of a sound presentation are aesthetically undesirable because they approach the volume at which sound becomes unpleasant or even painful (typically around 110 dB). Accordingly, there is a need for a new approach for processing audio signals for presentation in a high noise environment.